Door bolt with electric alarm

ABSTRACT

A door bolt with an electric alarm provides an alarm indication after a door bolt has been placed in the locked position and an intruder either severs the bolt, forces the door open or applies great force against the door.

I United States Patent 1191 1111 3,810,145 Gusaras May 7, 1974 [54] DOORBOLT WITH ELECTRIC ALARM 3,623,062 11/1971 Hawkins 340/274 3,263,0407/1966 Bliven 340/274 X [75] Inventor: Vlad Gusaras, Madlson, 2,521,0059/1950 Gundlach 340/274 ux 73 Assignee; O Industries, Inc Crystal Lake,2,725,437 11/1955 Fields et al. ZOO/61.67

Ill.

Primary Examiner-John W. Caldwell [22] Flled' 1972 AssistantExaminerWilliam M. Wannisky [2]] Appl. No.: 301,589 Attorney, Agent, orFirml(inzer, Plyer, Dorn &

, McEachran [52] US. Cl 340/274, 70/DIG. 49, ZOO/61.67 [51] Int. ClE05!) 45/12 57 ABSTRACT [58] Field of Search 340/274, 276; 70/129, 434,

70/438, DIG. 4O 49 7 200/6157, A door bolt w1th an electrlc alarmprovldes an alarm 6168 6193 indication after a door bolt has been placedin the locked position and an intruder either severs the bolt, [56]References Cited forces the door open or applies great force against thev UNITED STATES PATENTS 3,727,210 4/1973 Hawkins 340/274 14 Claims, 18Drawing Figures PATENTEDMAY 7 1974 SHEET 1 [1F 4 minnow 71914 3.810.145

DOOR BOLT WITH ELECTRIC ALARM SUMMARY OF THE INVENTION This invention isin the field of alarm devices and is for use in such places as homes,apartments, motels, and hotels.

A primary object is a door bolt with an electric alarm that provides analarm indication when an intruder tampers with a secured door bolt.

Another object is an alarm device that has an indicator such as a lampso that the operator of the device can tell when the device is in itsoperating mode.

Another object is an alarm device that will provide an alarm when thedoor bolt is severed, forced open, or when a large force is applied tothe door. Another object is an alarm device that gives an alarmindication only when an intruder tampers with the locked door bolt.

Other objects will appear from time to time in the ensuingspecification, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of oneembodiment of a door bolt with an electric alarm;

FIG. 2 is a sectional view along line 22 of FIG. 1;

FIG. 3 is a side view of FIG. 1;

FIG. 4 is a schematic diagram of the electric alarm circuit of thedevice;

FIG. 5 is a front view of an alternate form of the alarm device;

FIG. 6 is a top view of FIG. 5 with parts broken away;

FIG. 7 is a top view of the device shown in FIG. 5

. with the door bolt in a different position;

FIG. 8 is an electrical circuit diagram of the alarm circuit of thedevice shown in FIGS. 5, 6, and 7;

FIG. 9 is a front view of another alternate form of the device with thebolt in an unlocked position;

FIG. 10 is the same as FIG. 9, except that the bolt is now in the lockedposition;

FIG. 11 is a front view of the housing shown in FIG. 9 with the doorbolt removed;

FIG. 12 is a sectional view along line 12--12 of FIG. 11;

FIG. 13 is a partial view of the bolt of FIGS. 9 and 10 with the camportion shown in detail;

FIG. 14 is a sectional view along line 14-14 of FIG. 13;

FIG. 15 is a sectional view along line 15-15 of FIG. 10;

FIG. 16 is a side view of FIG. 9 with parts broken away with the bolt inan unlocked position;

FIG. 17 is a side view of FIG. 10 with parts broken away with the boltin a locked position; and

FIG. 18 is an electrical circuit diagram of the alarm circuit of thedevice shown in FIGS. 9 through 17.

DESCRIPTION OF THE PREFERRED EMBODIMENT Three forms of the door bolt andalarm device will be described, although the invention should not belimited to the precise structures shown. The various structures shown inFIGS. 1 through 18 include a door bolt, a door bolt housing, and analarm and detector means.

The alarm and detector means each include two detector switches, analarm device, and a power source.

The door bolt with electric alarm device in FIGS. 1

through 4 includes a door bolt housing 10 which is mounted on the door,an alarm and detector means 12 mounted to the door jamb or wall adjacentto the door and a door bolt 14 that travels in the door bolt housing 10and extends into the alarm and detector means 12. The door bolt 14 isshown in FIGS. 1, 2 and 3 in its locked position in the door bolthousing 10.

The door bolt housing 10 is mounted to the door by fasteners 16 such asscrews or the like, in the same position as a standard door bolt. Thehousing 10 has a channel 18, rectangular in shape except for twoelongated locking grooves 20 and 22, located at the far edges of thebolt channel. The door bolt 14, a generally straight rod, has a handle24 which slides in the bolt channel 18.

The alarm and detector means 12 includes a housing 26 which is mountedby appropriate fasteners 30 such as screws. The door bolt 14 enters thehousing 26 through an opening 32. Mounted in the alarm detector meanshousing 26 are a buzzer alarm device 34, an operating mode indicatorlamp 36, a detector switch 38, and an intruder switch 40 that also is analarm actuator,-and a battery power source 42. Although the alarm deviceis shown as a buzzer, it should be understood that various other alarmmeans are equally satisfactory.

The connections of these elements are shown in the electrical circuitdiagram FIG. 4. The battery power source 42 may be a nine volttransistor" battery and is connected to the operating indicator lamp 36through detector switch 38. The buzzer alarm device 34 is connected tothe battery power source 42 through detector switch 38 and intruderswitch 40.

The contacts of the detector switch 38 are normally open while thecontacts of the intruder switch 40 are normally closed. When the doorbolt 14 is in the unlocked position, the end 44 of the door bolt doesnot extend far enough into the housing 26 to engage the switch actuatorbutton 46 of the detector switch 38 or the actuating arm 48 of theintruder switch 40. In this position the switches will be in theirnormal contact modes with detector switch 38 open and intruder switch 40closed. The alarm circuit will then be in the condition shown in FIG. 4.Neither the operating indicator lamp 36 nor the buzzer alarm device 34will be operated.

As the bolt handle 24 of the door bolt 14 travels from its unlockedposition at elongated groove 20 at the right side of the bolt channel 18to the elongated groove 22 on the left side of the bolt channel, thedoor bolt 14 moves to the left and enters opening 32 of the housing 26.The door bolt 14 will contact the actuating arm 48 of switch 40 atroller wheel 50 attached to the actuating arm before contacting theswitch button 46 of switch 38. At this point the switch contacts ofswitch 40 will open while the contacts of switch 38 will remain open. Asthe door bolt is pushed farther to the left and the door bolt handle 24enters the left side of elongated groove 22, the end of the door bolt 44will contact switch button 46. The contacts of switch 38 will now close,and will remain closed due to the latching design of the switch,lighting lamp 36. This indicates that the alarm device is now inoperation. Since the door bolt 14 is still actuating the intruder switch40 through roller 50 and actuating arm 48, its switch contacts remainopen.

When the bolt handle 24 enters the left side of the elongated groove 22,the spring 52 of detector switch 38 is compressed as the end 44 of doorbolt 14 depresses switch button 46. As the operator releases the bolthandle 24, spring 52 of switch 38 pushes the door bolt 14 and attachedbolt handle 24 from the left side of elongated groove 22, where the bolthandle first entered the groove, to the right side of groove 22. The

switch button 46 is released with its switch contacts not being openeduntil the bolt handle 24 is unlocked by again moving it to the left ofgroove 22 in order to re-enter the bolt channel 18. The dimensions ofthe elongated groove are such that the bolt handle 24 must enter thegroove 22 at its left side to clear extension 28 of groove 22. Due toextension 28 of elongated groove 22, the groove 22 is wider at itsbottom than at its top where the bolt handle 24 first enters the groove.

If an intruder applies force to the door, the door bolt 14 will move inopening 32 toward the wall 52 in FIG. 2. The detector switch 38 willremain actuated because it is latched. However, the door bolt 14 willmove away from roller wheel 50, allowing actuating arm 48 to movedownward in FIG. 1 such that the intruder switch is returned to itsnormal closed position. Since the contacts of switch 38 are closed andthose of intruder switch 40 are also closed, the battery 42 deliverspower to the buzzer alarm device 34 alerting the occupants to thepresence of the intruder.

Similarly, if an intruder seversthe bolt in order to obtain entry, thedoor bolt 14 will fall downward in the opening 32, the detector switch38 remaining latched with closed contacts, but deactuating the intruderswitch 40. The contacts, of intruder switch 40 are closed as rollerwheel 50 is no longer in contact with the door bolt 14 and allows theactuating arm 48 to return to its normal position.

The structure shown in FIGS. 5, 6, 7, and 8 includes a door bolt housing110, a door bolt 112 and detector means 114 for determining the positionof the door bolt 112. The alarm means and the operating indicator lampmay be similar to that shown in FIGS. 1-4 and will not be discussed indetail. The battery 42, the buzzer 34, and the operating indicator lamp36 are shown in the electrical circuit diagram FIG. 8.

The door bolt housing 110, which is fastened to the door by means ofappropriate fasteners 116 has a bolt channel 118 with elongated lockinggroove 120 for the bolt handle 122. The door bolt housing 110 providessupport for the door bolt 112 which slides in the door bolt housing asthe door bolt handle 122 is moved in the bolt channel 118.

The door bolt 112 is thicker than that shown in FIGS. 1-4 and includes athin, rod-like extension, or bolt neck 130 at the end of the door boltwhich enters the detector means 114. A bolt sleeve 132 is mounted on thebolt neck 130 by means of a passage drilled through the center of thebolt sleeve 132. A spring 134 is placed over the bolt neck 130 in thepassage of the bolt sleeve between the washer 138 and the walls of thepassageway at 136. The spring 134 is selected to provide a small amountof tension to hold the bolt sleeve 132 against the door bolt 112 wherethe bolt originates.

The detector means 114 includes a detector switch 150, an intruderswitch 152 and a detector housing 154 that supports the switches and 152and is fastened to the wall or door jamb adjacent the door.'The detectorswitch 150 is mounted to the housing 154 by a bracket 156 and screws158. The intruder switch 152 is mounted to the housing 154 by a bracket160 and screws 162.

The detector switch 150 has normally open contacts when its actuator arm164 has no force applied to it, allowing the actuator button 166 to bein its extended or upward position. When force is applied against theactuator arm 164 depressing the actuator button 166, the contacts of thedetector switch 150 are closed.

The contacts of intruder switch 152 are also normally open when no forceis applied to actuating arm 168 such as not to depress actuator button170. When force is applied to the actuating arm 168, the actuator button170 is depressed and the contacts are closed.

The switches 150 and 152 are connected to the battery 42, the operatingindicator lamp 36 and the buzzer 34 by appropriate wiring means to formthe electrical circuit shown in FIG. 8. The battery 42 is connectedthrough detector switch 150 to the operating indicator lamp 36. Thebuzzer 34 is connected to the battery 42 through detector switch 150 andintruder switch 152.

The detector housing 154 includes a jam housing cam 172 where the boltsleeve 132 enters the housing 154. The jam housing cam 172 is a circularhole in the.

detector housing 154 with a beveled edge 174 on the inside opening ofthe detector housing 154. The bevel has a larger diameter on the insideof the housing than halfway through the housing. The bevel of the wallsof the jam housing cam 172 is similar to the neck of the bolt sleeve132.

When the door bolt 112 is in the unlocked position with door bolt handle122 to the right side of bolt channel 118, detector switch 150 andintruder switch 152 are both in their normally open position as shown inFIG. 8. Therefore, neither the operating indicator lamp 36 nor thebuzzer 34 is actuated.

When the door bolt 112 is placed in the locked position with door bolthandle 122 in elongated locking groove 120, the door bolt 112 and thebolt sleeve 132 extend into the detector housing 154 through the openingformed by the jam housing cam 172. The bolt sleeve 132 applies force tothe actuating arm 164 of the detector switch 150 as shown in FIG. 6. Theforce on actuating arm 164 depresses the actuating button 166, closingthe switch contacts of switch 150. With the contacts of switch 150closed, the operating indicator lamp 36 is actuated. This informs theoccupant or operator of the device that the invention is in theoperating mode. The switch contacts of switch 152 are still in theirnormally open position since the bolt sleeve 132 has applied no force tothe actuating arm 168 so as to depress the actuating button 170 ofswitch 152.

If an intruder attempts to force open the door, the door bolt 112 willmove toward jam housing cam 172 and 174 in the direction designated 176in FIG. 7. The bolt sleeve 132 moves a small distance and then contactsthe jam housing cam 172 at 174. As the door bolt 112 is pushed further,the jam housing cam 172 exerts a force on the bolt sleeve 132 in thedirection designated 178, overcoming the tension of spring 134. Thiscauses the bolt sleeve 132 to move in the direction 178, applying forceto the actuating arm 168 of the intruder switch 152. The actuating arm168 depresses the actuator button 170 of switch 152, closing itscontacts. Now, since both switches 150 and 152 are closed, the buzzer 34will be actuated by the battery 42, indicating the presence of anintruder.

The structure shown in FIGS. 9 through 18 includes a door bolt housing210, a door bolt 212, detector means 214 and alarm means which will notbe discussed in detail as they are similar to that shown in FIGS. 1through 9.

The door bolt housing 210 is very similar to that shown in FIGS. 5, 6,7, and 8 and includes a bolt channel 216 in which the bolt handle 218travels. The door bolt housing 210 is fastened to the door by means ofsuitable fasteners 220. The door bolt 212, a generally straight rod,moves in the door bolt housing 210 as the door bolt handle 218 is movedfrom its unlocked position to the far right in the bolt channel 216 tothe locked position with the door bolt handle 218 to the far left ofbolt channel 216 in locking groove 222. The door bolt 212 is rotated asthe door bolt handle 218 is placed in locking groove 222.

The detector means 214 includes a detector switch 224, an intruderswitch 226, a spring 228, shown in FIGS. 11 and 12, and a detectorhousing 230 to which the switches 224 and 226 are fastened by means ofsupport bracket 232. The detector switch 224 has normally open contactscontrolled by an actuator bat handle or button 234. When the actuatorbat handle 234 is snapped away from its normal position, the contacts ofswitch 224 close. The normal position of the actuator bat handle orbutton 234 is toward the door jamb in FIG. 16. The contacts of intruderswitch 226 are normally closed and are controlled by actuator button236. When the actuator button 236 is depressed, the switch contacts ofswitch 226 open.

The detector switch 224 and the intruder switch 226 are connected to thealarm means and power source by appropriate connecting means to form theelectrical circuit of FIG. 18. The battery 42 is connected to theoperating indicator lamp 36 through detector switch 224. The buzzer 34is connected to the battery 42 I through detector switch 224 andintruder switch 226.

The door bolt 212 when in the locked position enters the detectorhousing 230 through opening 238. A bolt cam 240 shown in detail in FIGS.13 and 14 is located on the end of the door bolt 212 that enters thedetector means housing 230. The bolt cam 240 is an L-shaped slot in theend of the door bolt to provide the correct actuating sequence of thedetector switch 224. When the door bolt 212 is in an unlocked position,detector switch 224 is not actuated because actuator bat handle 234 isnot snapped by door bolt 212. When the door bolt 212 is extended farenough into the housing 230 to reach the detector switch 224, theactuator bat handle 234 of switch 224 lines up with bolt cam 240 so asnot to be actuated as shown in FIG. 16. When the door bolt handle 218 isrotated and pushed downward into the locking groove 222 of bolt channel216, the door bolt 212 also rotates and bolt cam 240 engages theactuator bat handle 234 forcing the actuator bat handle 234 to snap overto position as shown in FIG. 17, thus closing the contacts. The contactwill remain closed until the door bolt is unlocked.

The door bolt 212 engages the actuator button 236 of intruder switch 226during the unlocked bolt movement before the bolt handle 218 is rotateddown into locking groove 222. Therefore, as the bolt 212 is extendedinto the housing 230, intruder switch 226 is actuated first, opening itscontacts. As the bolt is rotated into the locking groove 222, detectorswitch 224 is actuated and its contacts close. The battery 42 nowappears across the operating indicator lamp 36 and the lamp is actuated.The buzzer 34 is not actuated because the switch contacts of theintruder switch 226 are open.

As the bolt is extended into the housing 230 through opening 238 withthe bolt handle 218 travelling to the left in FIG. 10, the spring 228 isdisplaced by the bolt 212 as seen in FIGS. 12 and 15. The bolt 212 isunder tension from spring 228, although no movement of the door bolt 212will occur because the door bolt is held rigid by door bolt housing 210.

If an intruder tries to force open the door, the door bolt 212 will moveaway from the door jamb and opening 238 of housing 230 to the left inFIG. 15. As the door bolt 212 moves, the switch contacts of detectorswitch 224 remain closed. As the door bolt 212 is moved by the appliedforce of the intruder, actuator button 236 of switch 226 is released asthe movement exceeds approximately one-half the thickness or diameter ofthe door bolt 212. When actuator button 236 of intruder switch 226 isreleased, the switch contacts close, placing the battery 42 across thebuzzer 34, alerting the occupants that an intruder is present.

If the intruder severs the bolt, spring 228 will force the door bolt 212to the end of the opening 238 of housing 230 with the same results asforce applied to the door. The door bolt 212 will move away from theactuator button 236 of switch 226, which closes its contacts andactivates the buzzer 34. Therefore, whether the intruder applies forceto the door or severs the bolt, the buzzer 34 will be activated.

The structures shown in FIGS. 1 through 18 actuate an alarm when anintruder applies force to a door or severs the door bolt after the doorbolt is in the locked position. Through various bolt and detector switcharrangements, the presence of an intruder is detected by the position ofthe door bolt.

Whereas the preferred forms of the invention have been shown anddescribed herein, it should be realized that there may be manymodifications, alterations and substitutions thereto.

I claim:

1. In a door bolt with electric alarm, a door bolt, a door bolt housingassembly mounted to a door and carrying said door bolt as the door bolttravels between locked and unlocked positions, alarm means including apower source, an operating indicator and an alarm, means for detectingthe position of said door bolt including a detector switch and anintruder switch connected in circuit with said power source, operatingindicator and alarm, said detector switch having normally open contacts,which are moved to a closed position when said door bolt is moved to alocked position, completing a circuit between said power source andindicator, said intruder switch including normally open 7 switchcontacts connecting said alarm to said power source through the contactsof said detector switch, an actuating arm controlling the opening andclosing of said intruder switch contacts and a roller wheel fastened onsaid actuating arm and positioned for contact by said door bolt when thedoor bolt is in a locked position, movement of said door bolt in amanner other than normal opening or closing causing said intruder switchto complete an electrical circuit from said power source to said alarm.

2. The structure of claim 1 further characterized in that said alarm isa buzzer.

3. The structure of claim 1 further characterized in that said operatingindicator is a lamp.

4. The structure of claim 1 further characterized in that said intruderswitch and detector switch are positioned such that the opening of saidswitch contacts of said intruder switch occur before said door boltdepresses said actuator button of said detector switch.

5. The structure of claim 4 further characterized in that said door boltreleases said roller wheel and said actuating arm of said intruderswitch closing said switch contacts when an intruder applies force tothe door or severs said door bolt, said alarm actuated by the closing ofsaid switch contacts of said intruder switch and said detector switch.

6. The structure of claim 5 further characterized in that said door bolthousing assembly includes means for positioning said door bolt todepress and release the actuator button of said detector switch as saiddoor bolt is placed in the locked position and to depress and releasesaid actuator button as said door bolt is unlocked.

7. The structure of claim 6 further characterized in that the contactsof said detector switch are latched closed when said actuator button isdepressed and released by said door bolt when being locked and in thatsaid contacts are opened when said actuator button is depressed andreleased by said door bolt when being unlocked.

8. In a door bolt with electric alarm, a door bolt, a door bolt housingassembly mounted to a door and carrying said door bolt as the door bolttravels between locked and unlocked positions, alarm means including apower source, an operating indicator and an alarm, means for detectingthe position of said door bolt including a detector switch and anintruder switch connected in circuit with said power source, operatingindicator and alarm, said detector switch having normally open contacts,which are moved to a closed position when said door bolt is moved to alocked position, completing a circuit between said power source andindica tor, said intruder switch including a pair of normally opencontacts, an actuator button controlling the opening and closing of saidintruder switch contacts, and an actuator arm which, when displaced,actuates said actuator button, said door bolt including a bolt sleevefastened by'spring means on the end of said door bolt that enters saiddetecting means, with said detecting means including a housing having ajam housing cam, movement ,of said door bolt in a manner other thannormal opening or closing causing said intruder switch to complete anelectrical circuit from said power source to said alarm.

9. The structure of claim 8 further characterized in that said boltsleeve contacts said jam housing cam causing said bolt sleeve to applyforce to said actuating arm of said intruder switch when an intruderapplies force to the door or severs said door bolt and attempts to openthe door, said bolt sleeve continuing to apply force to said actuatingarm of said detector switch.

10. The structure of claim 9 further characterized in that said alarm isconnected to said power source through the switch contacts of saiddetector switch and said switch contacts of said intruder switch, saidswitch contacts of said intruder switch closing when said bolt sleeveapplies force to said actuating arm of said intruder switch, said alarmbeing actuated by said power source.

11. in a door bolt with electric alarm, a door bolt, a door bolt housingassembly mounted to a door and carrying said door bolt as the door bolttravels between locked and unlocked positions, alarm means including apower source, an operating indicator and an alarm, means for detectingthe position of said door bolt including a detector switch and anintruder switch connected in circuit with said power source, operatingindicator and alarm, said detector switch having normally open contacts,which are moved to a closed position when said door bolt is moved to alocked position, completing a circuit between said power source andindicator, said intruder switch including normally open switch contacts,with both said intruder switch and detector switch including an actuatorbutton controlling the opening and closing of said switch contacts, saidalarm being connected to said power source through the contacts of saidintruder switch and through the contacts of said detector switch, saiddetector means including a spring applying force to said door bolt in anormal direction to the door, said door bolt including a bolt cam at theend thereof extending into said detecting means, said bolt cam beingarranged in said door bolt so as to contact said actuator button of saiddetector switch only when said door bolt is in the locked position,movement of said door bolt in a manner other than normal opening orclosing said intruder switch to complete an electrical circuit from saidpower source to said alarm.

12. The structure of claim 11 further characterized in that saidactuator button of said intruder switch is depressed opening saidcontacts when said door bolt is in the locked position before said boltcam contacts said actuator button of said detector switch, said switchcontacts of said detector switch closing when said bolt cam contactssaid actuator button actuating said operating indicator.

13. The structure of claim 12 further characterized in that said doorbolt allows said actuator button of said intruder switch to be releasedwhen an intruder applies force to the door and said door bolt moves awayfrom said actuating button of said intruder switch or when intrudersevers said door bolt and said spring pushes said door bolt away fromsaid actuator button of said intruder switch.

14. The structure of claim 13 further characterized in that saidcontacts of said intruder switch close when an intruder applies force orsevers said door bolt and said door bolt releases said actuator button,said alarm being actuated by the switch contacts of said intruderswitch.

1. In a door bolt with electric alarm, a door bolt, a door bolt housingassembly mounted to a door and carrying said door bolt as the door bolttravels between locked and unlocked positions, alarm means including apower source, an operating indicator and an alarm, means for detectingthe position of said door bolt including a detector switch and anintruder switch connected in circuit with said power source, operatingindicator and alarm, said detector switch having normally open contacts,which are moved to a closed position when said door bolt is moved to alocked position, completing a circuit between said power source andindicator, said intruder switch including normally open switch contactsconnecting said alarm to said power source through the contacts of saiddetector switch, an actuating arm controlling the opening and closing ofsaid intruder switch contacts and a roller wheel fastened on saidactuating arm and positioned for contact by said door bolt when the doorbolt is in a locked position, movement of said door bolt in a mannerother than normal opening or closing causing said intruder switch tocomplete an electrical circuit from said power source to said alarm. 2.The structure of claim 1 further characterized in that said alarm is abuzzer.
 3. The structure of claim 1 further characterized in that saidoperating indicator is a lamp.
 4. The structure of claim 1 furthercharacterized in that said intruder switch and detector switch arepositioned such that the opening of said switch contacts of saidintruder switch occur before said door bolt depresses said actuatorbutton of said detector switch.
 5. The structure of claim 4 furthercharacterized in that said door bolt releases said roller wheel and saidactuating arm of said intruder switch closing said switch contacts whenan intruder applies force to the door or severs said door bolt, saidalarm actuated by the closing of said switch contacts of said intruderswitch and said detector switch.
 6. The structure of claim 5 furthercharacterized in that said door bolt housing assembly includes means forpositioning said door bolt to depress and release the actuator button ofsaid detector switch as said door bolt is placed in the locked positionand to depress and release said actuator button as said door bolt isunlocked.
 7. The structure of claim 6 further characterized in that thecontacts of said detector switch are latched closed when said actuatorbutton is depressed and released by said door bolt when being locked andin that said contacts are opened when said actuator button is depressedand released by said door bolt when being unlocked.
 8. In a door boltwith electric alarm, a door bolt, a door bolt housing assembly mountedto a door and carrying said door bolt as the door bolt travels betweenlocked and unlocked positions, alarm means including a power source, anoperating indicator and an alarm, means for detecting the position ofsaid door bolt including a detector switch and an intruder switchconnected in circuit with said power source, operating indicator andalarm, said detector switch having normally open contacts, which aremoved to a closed position when said door bolt is moved to a lockedposition, completing a circuit between said power source and indicator,said intruder switch including a pair of normally open contacts, anactuator button controlling the opening and closing of said intruderswitch contacts, and an actuator arm which, when displaced, actuatessaid actuator button, said door bolt including a bolt sleeve fastened byspring means on the end of said door bolt that enters said detectingmeans, with said detecting means including a housing having a jamhousing cam, movement of said door bolt in a manner other than normalopening or closing causing said intruder switch to complete anelectrical circuit frOm said power source to said alarm.
 9. Thestructure of claim 8 further characterized in that said bolt sleevecontacts said jam housing cam causing said bolt sleeve to apply force tosaid actuating arm of said intruder switch when an intruder appliesforce to the door or severs said door bolt and attempts to open thedoor, said bolt sleeve continuing to apply force to said actuating armof said detector switch.
 10. The structure of claim 9 furthercharacterized in that said alarm is connected to said power sourcethrough the switch contacts of said detector switch and said switchcontacts of said intruder switch, said switch contacts of said intruderswitch closing when said bolt sleeve applies force to said actuating armof said intruder switch, said alarm being actuated by said power source.11. In a door bolt with electric alarm, a door bolt, a door bolt housingassembly mounted to a door and carrying said door bolt as the door bolttravels between locked and unlocked positions, alarm means including apower source, an operating indicator and an alarm, means for detectingthe position of said door bolt including a detector switch and anintruder switch connected in circuit with said power source, operatingindicator and alarm, said detector switch having normally open contacts,which are moved to a closed position when said door bolt is moved to alocked position, completing a circuit between said power source andindicator, said intruder switch including normally open switch contacts,with both said intruder switch and detector switch including an actuatorbutton controlling the opening and closing of said switch contacts, saidalarm being connected to said power source through the contacts of saidintruder switch and through the contacts of said detector switch, saiddetector means including a spring applying force to said door bolt in anormal direction to the door, said door bolt including a bolt cam at theend thereof extending into said detecting means, said bolt cam beingarranged in said door bolt so as to contact said actuator button of saiddetector switch only when said door bolt is in the locked position,movement of said door bolt in a manner other than normal opening orclosing said intruder switch to complete an electrical circuit from saidpower source to said alarm.
 12. The structure of claim 11 furthercharacterized in that said actuator button of said intruder switch isdepressed opening said contacts when said door bolt is in the lockedposition before said bolt cam contacts said actuator button of saiddetector switch, said switch contacts of said detector switch closingwhen said bolt cam contacts said actuator button actuating saidoperating indicator.
 13. The structure of claim 12 further characterizedin that said door bolt allows said actuator button of said intruderswitch to be released when an intruder applies force to the door andsaid door bolt moves away from said actuating button of said intruderswitch or when intruder severs said door bolt and said spring pushessaid door bolt away from said actuator button of said intruder switch.14. The structure of claim 13 further characterized in that saidcontacts of said intruder switch close when an intruder applies force orsevers said door bolt and said door bolt releases said actuator button,said alarm being actuated by the switch contacts of said intruderswitch.